This invention relates to liquid drainage devices for fluid conduit systems. More particularly, this invention relates to devices for removing condensate from steam lines.
Steam piping systems must be provided with equipment to remove the condensate which accumulates as heat is lost from the steam. Generally, condensate removal equipment is located at low points or pockets in the steam piping and at regular intervals in the extended runs of the steam piping, as well as at steam-driven equipment which could be damaged by condensate. Older equipment, such as the widely employed inverted bucket condensate trap, has increasingly been replaced with more simplified orifice devices, for example, those devices described in U.S. Pat. Nos. 3,715,870 and 3,877,895, in which a plate having an orifice is positioned in steam lines enabling condensate to be forced through the small diameter orifice by the high pressure steam; when the orifice is properly sized, condensate obstructs passage of steam through the orifice in order to minimize steam loss while permitting drainage of the condensate.
U.S. Pat. No. 4,171,209 describes a device in which an orifice plate is unitarily formed in the body of a fitting which can be conveniently connected directly into the steam line, preferably downstream from a conventional Y-strainer which removes particulate debris from the accumulated condensate. While such unitarily formed orifice plate devices have been effective and proven to be commercially successful, the drilling of the small orifice required is a difficult process, and because the resulting fitting has an orifice of fixed length and diameter, a multiplicity of variously drilled bodies of fittings are employed to accommodiate variation in steam pressures in order to minimize steam loss through the orifice.